New Light on Dark Energy

Snapshot from a computer simulation of the formation of large-scale structures in the Universe, showing a patch of 100 million light-years and the resulting coherent motions of galaxies flowing towards the highest mass concentration in the centre. The snapshot refers to an epoch about 10 billion years back in time. The colour scale represents the mass density, with the highest density regions painted in red and the lowest in black. The tiny yellow lines describe the intensity and direction of the galaxy's velocities. Like compass needles, they map the infall pattern and measure the rate of growth of the central structure. This depends on the subtle balance between dark matter, dark energy and the expansion of the Universe. Astronomers can measure this effect using large survey of galaxies at different epochs in time, as shown by the new research. Credit: Klaus Dolag and the VVDS team.